Simplify the expression. $(-y+4)(y+4)$
First distribute the ${-y+4}$ onto the ${y}$ and ${4}$ $ = {y}({-y+4}) + {4}({-y+4})$ Then distribute the ${y}.$ $ = ({y} \times {-y}) + ({y} \times {4}) + {4}({-y+4})$ $ = -y^{2} + 4y + {4}({-y+4})$ Then distribute the ${4}$ $ = -y^{2} + 4y + ({4} \times {-y}) + ({4} \times {4})$ $ = -y^{2} + 4y - 4y + 16$ Finally, combine the $x$ terms. $ = -y^{2} + 0 + 16$